Integrated circuits are typically manufactured on disk-like semiconductor slices. There are certain types of manufacturing equipment that need to have the slice precisely centered in relation to them. Such equipment includes photoresist and develop spinners, since these devices rotate at a high speed. Conventionally, this type of equipment is loaded by air or by rubber band tracks and the slice is transported into a separately provided aligner or slice locator.
In modern integrated circuit slice fabrication, it has always been desirable to reduce contamination of the slice surface on which the integrated circuit is formed. One method for accomplishing this is to manipulate the silicon slice in a contaminant-free enclosure by a robot arm. However, using a robot as the slice transporter to ram the slice into a slice locator is not practical. Another approach using robot manipulation is to set the slice on another centering mechanism which does the alignment, picking the slice off this mechanism with the robot arm, and continuing on to the next workstation.
Thus, conventional solutions to centering using robot manipulation have the disadvantages of requiring a separate device that can cost several thousand dollars, further robot moves which have to be taught to the robot, and several additional steps of picking up and putting down the slice, all of which generate additional contaminating particles and slow down the process throughput.
A need has therefore arisen in the industry for a method and apparatus for aligning a slice relative to a robot end effector that does not require additional devices, is relatively simple to implement, and is compatible with robot manipulation